|
Reverse osmosis technology applied to certain effluents allows to operate a very high concentration, thus producing deionized water with no organic substances and an ultraconcentrate that is periodically
discharged and handed over to a third party for disposal or, as an alternative, further concentrated prior disposal using evaporation methods.
In this way “zero discharge” can be obtained.
The break-even point is represented by the discharge ion concentrations, which must be carefully analyzed before deciding to go for “zero discharge”: ion high concentration may make the pursuing of
this process non-advantageous in the end.
In comparison with a reverse osmosis system for water demineralization, these zero discharge systems are characterized by the fact that they work in a “closed concentrate loop”, with mounting saline
gradients and higher working pressures.
It is thus very important to correctly evaluate the operative conditions (pH, conductivity, pressure), instrumentally monitored and kept in the operative range through dosing of chemicals.
|
Typical zero discharge system flow chart
|
|
